MOST (Media Oriented Systems Transport) is a standard for vehicle-mounted electronic device network systems for use in multimedia. In MOST, an optical receiver circuit such as FOT (Fiber Optic Transceiver) is used, that receives a signal from an optical fiber to convert it into an electrical signal. With respect to FOT, it is expected to reduce power consumption.
In order to achieve low consumption current, a shutdown function is provided for a conventional optical receiver circuit. In a shutdown function, when a shutdown signal is input from the outside, the system comes into a shutdown state that leads to a state in which its consumption current is reduced. Thereafter, when a shutdown release signal is input from the outside, the shutdown state is released, and the system returns to a normal operational state.
One method for miniaturizing such an optical receiver circuit is proposed in Patent Document 1. In an optical receiver circuit described in Patent Document 1, an output from a photodiode is input to an output stage via a first stage amplifying part, an amplifier, a hysteresis comparator, and a buffer. A bias current is supplied to each circuit element from a bias circuit. When a reset signal transmitted on the basis of an output from the amplifier is input to a shutdown control circuit, the bias circuit comes into a shutdown state. The shutdown control circuit releases the shutdown state of the bias circuit on the basis of an output from the first stage amplifying part.    Patent Document 1: Japanese Published Unexamined Patent Application No. 2005-130173